What is AC waveform distortion?

The power supplies in electronics, both linear and switching, draw current only at the peaks of the AC voltage creating a characteristic ‘flat topped’ waveform.

The amount of distortion of a waveform can be quantified by its Total Harmonic Distortion (THD). Ideally, for high performance audio, studio and home theater systems, THD would be under 2%. In some locations measured THD has been 10 times higher than this!

All amplifiers, except Class A devices, draw current in response to the music waveform. ‘Flat topping’ restricts current delivery, leading to reduced dynamics, loss of articulation, bass extension and an anemic, uninvolving overall presentation.